A. His mother is unhappy because of the fact that his room is untidy.

B. His mother is unhappy because of his room is untidy.

C. His mother is unhappy because of his untidy room.

Both A & C are correct.

I won't be able to do anything if I have a quite room.

If we don't have a quiet room, I won't be able to do anything.

I will be able to do anything if I don't have a quiet room.

If I have a quiet room, I won't be able to do anything.

If we use the car all the time, we won't make the air dirty.

If we use the car all the time, we make the air dirty.

If we use the car all the time, we will make the air dirty.

If we don't use the car all the time, we make the air dirty.

Unless we don't leave now, we will miss the train.

We will miss the train if we leave now.

We still miss the train if we leave now.

Unless we leave now, we will miss the train.

I wanted to go but he wanted to stay.

I wanted to go and he wanted to stay.

I wanted to go so he wanted to stay.

I wanted to go or he wanted to stay.

Doesn't play soccer in the street.

Don't play soccer in the street.

Didn't play soccer in the street.

Won't play soccer in the street.

They plan to make those beach a clean and beautiful place again.

They are making this beach a clean and beautiful place again.

They are going to make this beach a clean and beautiful place again.

All are correct.

We should go out because it is very cold.

We can't go out now so it is very cold.

Let's go out although it is very cold.

We can't go out now because it is very cold.

The Red River is shorter than the Nile River.

The Red River is shorter the Nile River.

The Red River and the Nile River are two longest rivers in the world.

The Red River and the Nile River are longer than any other rivers in the world.

The police station is between the bookstore and the toy store.

The toy store is between the bookstore and the police station.

The bookstore is between the toy store and the police station.

The toy store is next to the police station and the bookstore.

A. Although doing morning exercises is good for your health, don't do it too hard.

B. Doing morning exercises is good for your health so don't do it too hard.

C. Doing morning exercises is good for your health but don't do it too hard.

Both A & C are correct.

If the sea level rose, some countries would disappear.

If the sea level rises, some countries will disappear.

If some countries will disappear, the sea level rises.

If some countries disappear, the sea level rises.

She won't succeed if she doesn't work hard.

If she works hard, she will succeed.

She will succeed unless she works hard.

She will succeed if she doesn't work hard.

A. It is a beautiful day because the sun is shining.

B. The sun is shining so it is a beautiful day.

C. Although the sun is shining, it is a beautiful day.

Both A & B are correct.

If he studied, he wouldn't fail the exam.

He failed the exam because he didn't study.

He will fail the exam if he doesn't study.

He didn't fail the exam because he studied.

If he hurries, he won't be late.

He won't be late unless he hurries.

He will be late unless he hurries.

He will be on time if he hurries.

If it doesn't rain, they will go to the party.

They won't go to the party if it rains.

They will go to the party if it rains.

They will not go to the party unless it rains.

A. The audience enjoyed the movie because it was exciting.

B. The movie was exciting so the audience enjoyed it.

C. Although the movie was exciting, the audience enjoyed it.

Both A & B are correct.

You will feel tired if you don't eat breakfast.

If you eat breakfast, you won't feel tired.

You will feel tired unless you eat breakfast.

You won't feel tired if you eat breakfast.

If she doesn't get sick, she will go to the concert.

She won't go to the concert if she gets sick.

She will go to the concert if she gets sick.

She will not go to the concert unless she gets sick.

If he doesn't work overtime, he won't finish the project.

He won't finish the project unless he works overtime.

He will finish the project unless he works overtime.

He will finish the project if he doesn't work overtime.

We will cancel the picnic if it rains tomorrow.

If it doesn't rain tomorrow, we will cancel the picnic.

We won't cancel the picnic unless it rains tomorrow.

We will not cancel the picnic if it rains tomorrow.

If he doesn't study hard, he won't pass the exam.

He won't pass the exam unless he studies hard.

He will pass the exam unless he studies hard.

He will pass the exam if he doesn't study hard.

A. We should go for a walk because the weather is nice.

B. The weather is nice so we should go for a walk.

C. Although the weather is nice, we should go for a walk.

Both A & B are correct.

If he doesn't finish work early, he won't go to the gym.

He won't go to the gym unless he finishes work early.

He will go to the gym unless he finishes work early.

He will go to the gym if he doesn't finish work early.

A. Everyone wants a piece because the cake is delicious.

B. The cake is delicious but everyone wants a piece.

C. Although the cake is delicious, everyone wants a piece.

D. Everyone wants a piece because of the cake is delicious.

If she doesn't save enough money, she won't travel to Paris.

She won't travel to Paris unless she saves enough money.

She will travel to Paris unless she saves enough money.

She will travel to Paris if she doesn't save enough money.

You will improve your grades if you study regularly.

If you don't study regularly, you won't improve your grades.

You will not improve your grades unless you study regularly.

You will improve your grades unless you don't study regularly.

If she doesn't pass the exam, she won't be happy.

She won't be happy unless she passes the exam.

She will be happy unless she doesn't pass the exam.

She will be happy if she doesn't pass the exam.